How/ What to do with the railing?
This is a tough one. Above all take measurements from a wall where spindles and main post set. The main end post is probably hollow inside, with a pair of 1x4's inside that stick down, but you won't really know untill you take up. I would cut flush with the floor, and then split the old and put back new inside the post and down under. Pull all the railing out,set aside, and forget it for now. Concentrate on a good looking hardwood floor job. You may have to use dowel pins on the spindles on the put back, but the main post is the dark horse when anchoring. Bernie